Apparatus for treating gases containing sulfur dioxid.



JOHN L.I TUETs,.oE BOSTON, MASSACHUSETTS.

APPARATUS FOR TREATING To all whom it may concern:

Be it known that I, JOHN L. T UFTS, a citizen of the United States, residing at Boston, inthe county of Suifolk and State of Massachusetts, have invented certain new and useful Improvements in Apparatus for Treating Gases Containing Sulfur Dioxid, of which the following is a specification. y

The object of this invention is to provide an apparatus by means of which dilute sulfur dioxid such as results from pyritic smelting operations or the like may be rendered availa le for use in various chemical processes, as for instance, in the manufacture of paper pulp by the suliite process, the production of sulfuric acid, etc. rI`his object is accomplished in the preferred embodiment ofthe invention by passing the dilute' gas rich in oxygen upwardly through a bed of hot ore in suitable pyrites burners, whereby oxygen is consumed and the percentage of sulfur dioxid largely increased. If as is usually the case the dilute gas is subject to wide fluctuations either in respectv toconcentration of sulfur dioxid or temperature, it is preferred to subject the saine to an equalizing operation before enriching it. The initial high temperature of the gas is conserved as far as practicable' throughout the treatment.

In order that the inventionmaybe clearly understood the same will ,be described by way of example as applied to certain specific conditions wherein'the gases aresubject to wide fluctuations both of concentration `and temperature, it being understood^tha`t the mode of application of the invention will vary with the specific conditions of production of the gas, .and with the requirements of the process of its utilization.

Under the specific conditions referred to thedilute sulfur dioxid is yderived from a set' of pyritic smelters and is subject toa periodicalv variation in concentration from 2% to 14% of sulfur dioxid, the usual average concentration being approximately 4%. The concentration variesin accordance with the stage of the operationl as follows: After the introduction of the freshcharge but before its ignition the concentration of sulfur dioxid is very low, increasing ra idly tothe time of full ignition, and then fa ing as the sulfur is burned out, this variation being repeated for each charge. The percentage of sulfur dioXid varies not only with the stage of the operation but also in accordance with the quantity land composition of the charge, and ac- Speecation of Letters Patent. Application filed July 29, 1907. Serial No. 386,160.v

GASES CONTAINING SULFUR DIOXID.

Patented June 16, 190s.

cording to whether the smelters are running hot or cold. The percentage of oxygen varies inverselyas the sulfur dioxid, from 19% to 7%.- The temperature of the gas varies from 400 to 1500o F., according to theperiod of the charge, averaging' about 1,000o F. The average interval between maximum and minimum temperature of the gases, and between maximum and minumum concentration of sulfur dioxid, is nine minutes, ,but varies from four to thirty minutes.

In order to `render a gaseous product of this character available for commercial uses, it is necessary .tha-t it should be subjected to an equalizin v operation. In order to render it availab e for the specific use of the production of sulfuric acid by means of an iron oxid contact mass, in which case the best practice requires a uniform gas containing 6% vsulfur dioxid at a uniform temperatureof 1150 F., I may proceed as folows:

The gas from the smelters is conducted lirst through a heavy-walled dust-chamber of masonry surrounded by a shell of sheet-iron, a space beingI left hetweenthe masonryand the iron and filled with a 'heaty insulatingy material such as, kieselguhr. From the dustchamber the gas `is led' to any equalizer, which may comprise a thick brick-walled chamber having a heat f insulatingy coating and coveredy with sheet-iron preferably the equalizer is provided interiorly with' a filling orchecker-work pfrefractorybrick, tile or the like. Thegcapacityr 'of the ,equalizer should be sufficient to hold the gas-delivered during an appreciable period, in ,order to reduce the variation in` its composit1on;and' it should furthermore be' ofjsuch heat capacity and design-that the temperature variation can be eliminatedy tothe extent desired. The lueconnecting the dust-chamber with the'equalizer is provided with a suitably controlled inlet for air, and sufficient air is introduced at the periods of the operation in which the gas is delivered of high concentration to suitably reduce the excess of sulfur dioxid. Preferably the gases are conducted through the apparatus under slight Suction, 'in which case the air mayl readily be admitted as desired. g j v yThe gaseous product flowing from the equalizer is as compared with the gas from the smelters moderately uniform in .tem-

erature and concentration; this highly iieated gas is introduced into a set of suit- ,out by reason of the These burners are preferably heavy-walled,

4form of` installation embo entering above the avoid burning them high temperature.

able pyrites burners, grate bars in order to heat insulated and sheathed with iron, and

of such-form as to provide a deep bed of cinder above the grate bars, affording dise tributing space for the gas. In these burners the combustion becomes more intense when the sulfur dioxid is low and the oxygen high and less intense when these conditions are reversed, theresul't being that the final -gas from the`burnersis of approximately uniform high tem 15 erature andA concentration, and is suite for direct introduction into an iron oxid contact mass 3, it is also suitable f for direct introduction into a Grlover tower and sulfuric acid chambers, or into the sulfite digesters; or after suitable cooling and cleaning for introduction into a latiii'uin contact mass.

v or a full understanding of the invention reference is made to the accompanying drawing wherein the figure is a (plan View of one ying the invention, the upper portion of the equalizer being `broken away. `Y

smelting furnaces 1 represents a group of for pyritic ores, the gases I-n said drawing from/which are discharged through flues 2` --into a common flue 3 leading to a dust chainber4.

5 represents `the equalizer, having double walls, 6, 7 for heat-insulation, and interiorly filled with checker-work 8y on either side of a partition 9.

10 represents anzair-inlet located in the' gas flue between the dust chamber and the equalizer. From the equalizer the gases How directlyto the burners represented at 11, and the final gases are conveyed from the I burners through the iiueA 12 for further utilization. s The' expression fcombustion of sulfur occurring in 'the `claims is intended to cover .the combustion ofv 2. Apparatus for producing sulfui` dioxid free sulfur, and also the I. combustion of combined sulfur in sulfidY ores; inthe latter chamber and burner.

. of burner,

, and burner.

of commercially uniform temperature andy concentration, comprising al furnace, an equalizing chain er of relatively large capacity for` rendering the gas from said furnace more nearly'uniform in teinyritic smeltiiig perature and concentration, a burner for the combustion Ofsulfur, and gas conduits con-` necting said smelting furnace, equalizing 3. Apparatus for producing sulfur dioxidy of sulfur dioxid, an equalizing chamber of relatively lar e capacity for rendering the gas morenear y uniform in temperature and concentration, a burner for the combustion ofl sulfur, gas conduits connectingsaid source sulfur dioxid, equalizing chamberl and gases Apassing 'to said equalizing chambenf 4. pparatus for producing sulfur dioxid of commercially uniform temperature and` concentration, comprising a source of dilute sulfur dioxid, a dust separator, an equalizing chamber of relatively large capacity for 'rendering thel gas more. nearly .uniform in temperature and concentration, a burner for the combustion ofy sulfur, extending .between said dioxid, vdust separator,

and "gas conduits source of sulfur equalizing chamber 5. Apparatus for producing sulfuri'dioxid ofl commercially uniform temperaturefand concentration, comprising a source of dilute sulfur dioxid, an equalizing chamber ofrelatively lar e capacity for rendering the gas more near y uniform in temperature and concentration, a refractory filling for said equalizing chamber, a burner forv the combustion of sulfur,v and gas conduits connecting said source of sulfur dioxid, equalizing chamber and burner.

and means for admitting air to the commercially uniform temperature and concentration, comprising a source of dilute 6. Apparatus for producing sulfur .dioxid 'i of commercially uniform4 temperature and concentration, comprising 'a source of dilute sulfur dioxid, an equalizing chamber of relatively larve capacity for rendering the gas more near y uniform in temperature'and convcentration, a refractory lling for said equal- 'izing/.chamber and a heat insulatin covering therefor, a burner for the combustion of sulfur, and of sulfur dioxid,. equalizing chamber and burner.

,l 'In testimony whereof, I affix my signature :in presence of two Witnesses.

JOHN L. TUFTS.

Witnesses: V

' GEO. J. TUFis,

EVERETT E. BRAINARD.

gas conduits connectingsaid source` 

